Ex2 Vascular Dx Flashcards
Thoracic/Abdominal aorta is most often
aneurysmal
- outpouch of tissue (all 3 layers) that fills with blood
- 50% increase in diameter
TAA - rupture - survival rate
25%
TAA - dissection: initiating event
tear in intima
-forms false channel
TAA - dissection most commonly happens in
thorax in the ascending aorta
most common risk factors in TAA
80% - Atherosclerosis
19% - family hx of aneurysmal dx
Smoking, Male, Older age, HTN
Inherited disorders assoc. with TAA
Marfans Syndrome
Ehler’s Danlos syndrome
(ED syn: flexible joints, skin elastic skin, bruise easily)
Bicuspid aortic valve
marfans syndrome
hereditary connective tissue disorder Fibrilin-1 gene - matrix destruction CHEMICAL function (not mechanical) - causes structural weakness in aorta
Bicuspid aortic valve
most common congenital anomaly resulting in aortic dissection/dilation
Crawford Classification Type I
All/most of descending thoracic aorta + upper abdominal aorta
Crawford Classification Type II
All/most of descending thoracic aorta + most of abdominal aorta
Crawford Classification Type III
Involves lower portion + abdominal aorta
Crawford Classification Type IV
Most of abdominal aorta including visceral segment
Most difficult TAA to treat
Crawford II + III
*crosses diaphragm
Dissecting aneurysms are classified by
Debakey Classification
Debakey I
formed a false track all the way up/down entire length of aorta
Debakey II
Tear = ascending
Debakey IIIa
Tear = intimal + stays on descending aorta
Debakey IIIb
Tear = intima + entire length of that side
S/S TAA
Asymptomatic
*impingement of aneurysm on adjacent structure may cause symptomatology on assoc. location
TAA with s/s hoarseness
impingement on R laryngeal nerve
TAA with s/s stridor
Compression of trachea
TAA with dysphagia
compression of esophagus
TAA with facial edema
compression of superior vena cava
S/S TAA dissection
acute, severe, sharp pain in anterior chest, neck or between shoulder blades
TAA dissection presents with shock
(severe hypotension)
-prognosis = poor
decreased peripheral pulses
Complications of TAA dissection
stroke, ischemic peripheral neuropathy, paraplegia, MI, GI ischemia, renal artery obstruction
*cardiac tamponade
Diagnosis of TAA
CXR (widening mediastinum)
TE-Echo + doppler flow (highly sensitive+specific)
predictors of post-thoracic aorta surgery
predictors of resp failure:
Smoking + COPD
Tx TAA
Surgical repair Type A Ascending aorta Aorta Arch Type B if aneurysm > 5cm Medical Tx: Type B < 5cm
Type A Dissection
Ascending aorta +/- arch
Mortality: Type A Dissection
27% after repair
56% if not repaired
Type B dissection
Ascending aorta NOT involved
Ascending + aortic arch dissection
emergent/urgent surgery
TAA - which is associated with better outcomes?
Type B: Descending thoracic aortic dissection
Which TAA requires cardiopulmonary bypass?
Aortic Arch
+hypothermia
+circulatory arrest
*neurological deficits post repair
Most important risk of paraplegia/renal failure with aortic cross clamping
Duration of clamping aorta
*under 30 minutes = almost no paraplegia
Risks assoc.: surgical resection of thoracic aortic aneurysm
spinal cord ischemia MI/HF coagulopathy renal failure 30% respiratory failure 50%
Lower 2/3 of spinal cord is supplied by
Artery of Adamkiewicz
(AAA)
Ischemia: Anterior spinal artery syndrome
HD response to X clamping
Increased BP, SVR, preload (CVP, PAOP, LVED), CSF pressure, myocardial contractility, coronary blood flow
*no increase in HR means: decreased CO
Tx - increase CO from X-clamp
Vasodilators: SNP, NTG
Tx goal during X-clamp
Myocardial preservation
-decrease afterload, normalize preload, coronary blood flow, contractilty
Blood flow distal to clamp depends on
perfusion pressure
HD response to unclamping
decrease in SVR/BP
LVEDV decreases
CO changes - unclear
myocardial blood flow increases
Goal during unclamping
Gradual decrease to avoid hypotension (metabolic waste/lactate buildup)
Monitoring during TAA cross clamping
R radial A line
Femoral Artery A line
Cerebral perfusion during TAA cross clamping is monitored via
R radial A line
Renal/spinal cord perfusion during TAA cross clamp is monitored via
femoral artery A line
Goal MAP above X-clamp
100mmHg
Goal MAP below X-clamp
> 50 mmHg
Monitor neurologic function during X-clamp
via SSEPs
Monitor cardiac fxn during x-clamp via
TEE, pulm artery catheter
How is renal protection performed in X-clamp for TAA?
40 Celsius LR + 25g mannitol/L directly into renal artery via surgeon
post op management TAA
epidural analgesia: neuraxial opioids
do NOT want LA in epidural (masks anterior artery spinal syndrome)
What is common and must be managed in post-op of TAA X-clamp?
HTN
Tx: NTG, SNP, labetalol, hydralazine, BB
Tx AAA
surgery if AAA > 5.5 cm
Serial U/S: < 5.5 cm
if increasing in size >.6-.8 cm/year, surgery indicated
Smoking + close to threshold: surgery indicated
Preop evaluation for AAA
- optimize comorbid conditions
- copd: minimize resp infxn, etc.
- caution in severe resp/renal dysfxn
1 cause of post-op deaths (AAA)
MI
Classic triad of ruptured AAA
Hypotension
Back pain
Pulsatile mass
Ruptured AAA - tx depends on
stable/unstable/suspected rupture
Ruptured AAA - tx if stable
- exsanguination may be prevented by clotting + tamponade effect of retroperitoneum
- euvolemic resuscitation deferred
ruptured AAA - tx if unstable
- require immediate surgical intvn
- give uncrossed/unmatched blood
- no time to optimize preop conditions
ruptured AAA - tx if suspected rupture
same as unstable
AAA - invasive monitoring during surgery
PA catheter
Echo - assess response during/after X-clamp
GETA - benzo + narcotic
AAA - when is epidural safe?
If PLANNED AAA repair
Risk of AAA + TAA repair post-op
spinal cord injury
-from 12h-21d
AAA vs. TAA main intra-op difference
AAA: need DL ETT
